<template>
  <div>
      <router-link tag="div" to="/" class="header-abs" v-show="showAbs">
        <div class="iconfont header-icon">&#xe685;</div>
      </router-link>
      <div class="header-flexd"  v-show="!showAbs" :style="opacityStyle">
           景点详情
            <router-link to="/">
                <div class="iconfont header-flexd-icon">&#xe685;</div>
            </router-link>
      </div>
  </div>
</template>

<script>
export default {
    name:'DetailHeader',
    data(){
        return {
            showAbs:true,
            opacityStyle:{
                opacity:0
            }
        }
    },
    methods:{
        scrollHander(){
            const top = document.documentElement.scrollTop
            if (top > 60 ) {
                let opacity = top / 140
                opacity = opacity > 1 ? 1 :opacity
                this.opacityStyle = { opacity }
                this.showAbs = false
            }else{
                this.showAbs = true
            }
        }
    },
    mounted () {
        window.addEventListener( 'scroll', this.scrollHander)
    },
    deactivated(){
        window.removeEventListener( 'scroll', this.scrollHander)
    }
}
</script>

<style scoped>
    .header-abs{
        position: absolute;
        left: .2rem;
        top: .2rem;
        width: .8rem;
        height: .8rem;
        line-height: .8rem;
        text-align: center;
        border-radius: .4rem;
        background: rgba(0, 0, 0, .8);
    }
    .header-icon{
        color: #fff;
        font-size: .4rem;
    }
    .header-flexd{
        position: fixed;
        top: 0;
        left: 0;
        right: 0;
        font-size: .32rem;
        height: .86rem;
        line-height: .86rem;
        text-align: center;
        color: #fff;
        background: #00bcd4;
    }
    .header-flexd-icon{
        position: absolute;
        top: 0;
        left: 0;
        width: .64rem;
        text-align: center;
        font-size: .4rem;
        color: #fff;
    }
</style>